1. Field of the Invention
The present invention relates to a sliding type mobile terminal such as mobile phones, mobile wireless communication equipment and the like, in which a first housing and a second housing are slidably coupled together.
2. Description of the Related Art
Recently, a one segment receiving service for mobile phones and mobile wireless communication equipment, which has captured attention as a service unique to terrestrial digital TV broadcasting, has started to be offered, and this service is commonly known as “One Seg”.
“One Seg” is a service realized by Japan's exclusive broadcasting system that splits a 6-megahertz band for terrestrial digital TV broadcasting into 13 segments to be sent. The middle segment of the 13 segments alone provides images, voice, and data. Further, what is different from normal TV is the advantage of receiving TV images in an undisturbed manner even while on the move. A further increase in the number of users is expected. Consequently, it is expected that a TV receiving function will be indispensable to the mobile phones and mobile wireless communication equipment.
On the other hand, the telephone call function of the mobile phone continues to be its main function. Further, because of its portability, smaller size and lighter weight have become important merchandising factors. In view of emphasis on usability, the mobile phone is vertically long with its width restricted.
When the display part is fixed in a vertically long state, to display an image horizontally long, it was necessary to give a reduced display to fit it into the vertically long screen or see the entire image by horizontal scroll operation.
For example, as shown in Japanese Unexamined Patent Application Publication No. 2006-115109, there is known a mobile information terminal composed of a body with an operating part and a cover superposed on the operating part side of the body and slidable along the operating part from the superposed state. In such sliding type mobile information terminal, when the cover in the superposed state on the body is held horizontally so that the display part provided on the cover may be in a horizontally long state, TV reception in the horizontally long state is possible.
Incidentally, contrary to the conventional analog broadcasting, the terrestrial digital TV broadcasting provides the user with what is called two-way service such that the user can participate in a quiz program on TV or to do TV shopping and make bank remittance through TV.
When viewing on terrestrial digital TV broadcasting through the mobile phone and the like is made possible, operating the keys at the operating part while viewing images at the display part becomes all the more necessary.
However, the terminal disclosed in the Japanese Unexamined Patent Application Publication No. 2006-115109 has only simple operating keys provided on the cover. Further, if the user holds it in the horizontally long state with the cover being slid to show the display part, the operating part is also turned by 90° so that denotation on the operating keys is positioned at the 90° turn as seen by the user. In addition, because the operating key arrangement differs from the usual arrangement, there was a problem that made an input operation extremely difficult.
In view of this, for example, in Japanese Unexamined Patent Application Publication No. 2003-338866, the mobile phone comprises a body housing a group of buttons such as dial buttons as well as various electronic circuits, and a display part of the same size as the body to enable it to be lapped thereon and fitted. The body is provided with a pin having a circular plate attached on top of a protrusion at the upper part of the surface side of the body, while the display part is provided with a cam part from the upper end to a substantially central position in the vertically long direction of the back surface side of the display part, the cam part being made up of a groove with a T-shape cross part to fit the pin provided on the body. The pin is inserted into the cam part of the display part, thus providing a slidable structure.
In the mobile phone of such construction, there is an advantage of performing normal key operation with its display part in the horizontally long state where receiving a telecast of two-way service such as TV shopping and when preparing mail in English.
However, in the mobile phone of Japanese Unexamined Patent Application Publication No. 2003-338866, the pin which is a pivot of sliding movement and rotation of the display pail is positioned at the upper end of the body, and there is only one pin for the display part to slide and rotate by being held by a single hand, causing a poor balance and thus creating a problem of growing ricketiness over years. Further, since the pin is located at the upper end of the body, when the display part is placed in the horizontally long state, the upper end of the display part is placed further above the upper end of the body, causing a problem of poor stability when the body is placed on the desk.
Conversely, when the pin is positioned lower from the upper end of the body downward to increase a sense of stability, the region for the operating part has to be made smaller, so that ideal button arrangements could not be hoped for, resulting in poor operability. To prevent this would necessitate enlarging the exterior shape of the product, then giving rise to a problem of worsening portability.